不同海拔对干热河谷土壤微生物量及活性的影响  

Soil microbial biomass and activity along an altitudinal gradient in dry-hot valley

作　　者：薛萐[1,2,3] 李鹏[1,2] 李占斌[1,2,3] 刘国彬[1,3] 郑郁[2] 

机构地区：[1]西北农林科技大学水土保持研究所黄土高原侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]西安理工大学西北水资源与环境生态教育部重点实验室,陕西西安710048 [3]中国科学院水土保持研究所,陕西杨凌712100

出　　处：《中国环境科学》2011年第11期1888-1895,共8页China Environmental Science

基　　金：国家自然科学基金资助项目(40801094;40971161);国家"973"项目(2007CB407205);西北农林科技大学基本科研业务费青年项目(QN2009080)

摘　　要：以四川宁南县金沙江下游的河谷地带为研究区域进择不同海拔下的土壤为研究对象，研究不同海拔下土壤微生物量及其活性的变异特征．结果表明，在干热河谷区，海拔对微生物量、基础呼吸强度、诱导呼吸强度（SIR）影响显著，且随着海拔高度的升高，上述指标呈显著线性增加．在海拔705～1005m处随着干热风影响的减少，微生物量及其活性逐渐增加，其后随着海拔的继续升高，干热风影响降低，微生物量及其活性总体趋于稳定．海拔1005～1400m可以作为是干热风影响的过渡区微生物量、基础呼吸强度、SIR具有明显的干湿季变化且变化规律相似，其中干季微生物量及其活性显著低于湿季．干季代谢商（qCO2）随海拔先降低后升高并趋于稳定，湿季没有显著差异．干季和湿季土壤微生物量与理化属性具有较强的相关性，可以作为评价土壤肥力的指标．上述研究结果表明，在金沙江干热河谷区，干热风是影响土壤微生物量及其活性的主要因子之一，从生态恢复角度出发，应该尽可能的减少干热风和水分对土壤和植被的胁迫作用，促进该区域生态的可持续性发展．The difference of soil microbial biomass and activity along an altitudinal gradient were investigated at lower branch of Jinsha River in Ningnan County. The results showed that elevation had significant effect on soil microbial biomass, microbial respiration and metabolic quotient （qCO2） in the dry-hot valley; they increased linearly with the increase of elevation. In the lower elevation （705-1005m）, soil microbial biomass and activity increased with the increase of elevation; the effect of dry/hot wind decreased with the increase of elevation, soil microbial biomass and activity tended to be stable. Elevation between 1005 and 1400m could be considered as the transition region. Soil microbial biomass, basal respiration and induced respiration presented obviously changes between wet and dry season, and usually a higher value was found in wet season. In dry season, qCO2 firstly decreased with elevation, then increased and thereafter tended to be stable, while no remarkable changes was observed in the wet season. Correlation analysis showed that soil microbial biomass was significantly correlated with the physico-chemical properties; thus soil microbial biomass and activities could be useful for reflecting soil fertility. The results suggested that in the Jinsha river dry-hot valley, dry-hot wind was one of the main factors limiting the soil microbial biomass and activities. Thus taking appropriate measures to reduce the effect of dry-hot wind on vegetation and soil is important for ecological sustainable development.

关 键 词：干热河谷地区 海拔 土壤微生物量 

分 类 号：X172[环境科学与工程—环境科学]